Smart thermostats are often one of the first smart home devices people consider getting, and for good reason. Unlike some smart home products with dubious benefits (Wi-Fi-enabled weather-predicting toaster, anyone?), the payoff is clear: Smart thermostats keep your home's temperature comfortable without the need for constant adjustments; they can also curb your heating and cooling bills. But just how much money will a smart thermostat save you? And is it easy to install and operate?
While some traditional digital thermostats are programmable to a certain extent—i.e., you can schedule temperature changes—smart thermostats do that and much more. Some can detect when you're at home or away, or learn your habits to adjust energy use. Many smart home thermostats can also be controlled from an app on your phone, so you can bring the house to the perfect temperature if you're heading home from work early, or kick up the AC for your cat if a surprise heat wave hits while you're on vacation.
Comfort and convenience aside, a smart thermostat really does curb your heating bill, too. One study by Nest found that homeowners who use the company's thermostat save 10% to 12% on heating costs and 15% on cooling. Plus, many local cities and utility companies offer rebates of $100 or more for installing these products; some will even give you a free smart thermostat if you sign up for certain plans. (You can search for deals in your area at the rebate finders pages for Ecobee or Nest.)
How to install a smart thermostat
Installation of most smart thermostats—including Nest, Ecobee, and Honeywell Lyric—are billed as DIY, with detailed videos and instructions on the product websites. That said, your success will depend on your skills and your home's wiring.
According to Dave Miller of Superior Heating and Air in Bluffton, SC, thermostat wiring is different from wiring in other parts of the home because wire colors are not always standard.
"The common wire is typically a blue wire, but I have seen it as green, black, and others," Miller says. "That’s why you have to know what you're doing."
Improper wiring isn't just a headache, it can also cause big problems.
"If you hook up the wrong wires, it could burn up the new thermostat, or the HVAC system low-voltage controls," Miller explains. "Or it may power up, but it could turn on heat and cooling at same time."
Bottom line: If you dive in but get confused, it might be worth calling in an electrician, whom you can expect to pay $100 to $150.
What's the best smart thermostat for you?
Here are three of the leading brands of smart thermostats, along with pricing, pros, and cons to help you find the right one for you.
The Nest is the granddaddy of smart thermostats, on the market since 2011. Its key feature: a learning algorithm that notes when you change the temperature and adopts those patterns going forward. Plus, its motion sensors can tell where you are in the home so it can save its energy for the right places. Last but not least, it can be integrated with many smart home devices, including Nest security cams, Philips Hue lights, Google Home speakers, and more.
So if Nest notices you're not home but you've left the lights on, it can tell your smart lights to turn off. Or if you're feeling chilly, you can tell Google or Alexa to turn up the heat.
Pros: The pioneer in this field, Nest is now a classic. Its reliability and learning capability mean Nest is easy to use for people who want a "set it and forget it" smart home experience.
Cons: It's more expensive than other options on the market, plus it's not compatible with all homes (if you open your thermostat and see thick, stranded wires held together by nuts, that's a no-go).
Best for: Beginning smart home users, particularly those with a Google Home or Alexa, with which it's compatible (it is not compatible with Apple HomeKit).
The Honeywell Lyric does most of the things the other industry leaders do—it programs and controls temperature remotely—at less than half the price.
Pros: Great price, and it interfaces with Amazon Echo and Apple HomeKit.
Cons: Unlike Nest, it cannot learn your patterns, although it does employ geofencing, a technology to detect when and where you are at home, to optimize temperature. It also does not interface directly with Google Home.
The Ecobee 4 takes Ecobee's previous offering up a notch by including a fully functioning, built-in Amazon Echo smart speaker. That means this smart thermostat is voice-activated: You can ask it to turn down the heat or do any of the things Alexa can do, from playing music to reporting the weather. So if you're dying for a smart speaker and a smart thermostat, this is a great two-for-one deal. Still, the previous versions without Echo will work with Apple HomeKit and other smart home hubs.
Pros: The big advantage, other than the Amazon Echo, is that it comes with a wiring kit that makes installation way easier in homes without a common wire.
Cons: It does not have Nest's learning capabilities, costs more than the Lyric, and cannot communicate directly with Google Home.
Best for: People who are pining for a smart speaker, or users who don't mind having to create temperature programs rather than have the device "learn" what they like.